Concealed grid system

ABSTRACT

A suspended ceiling grid structure for use in a concealed type of grid system, in which the grid structure may include a pair of main runners between which a plurality of ceiling tiles are to be supported, two spaced runner means extending between the main runners for supporting such ceiling tiles therefrom, with at least one of said runner means including downwardly movable means for supporting the associated ceiling tile, with such tile being removable from the grid structure following downward movement of said movable means.

Unite States atent 11 1 Jahn 1 51 Oct. 15, 1974 i 1 CONCEALED GRlDSYSTEM [75] Inventor: Reinhardt H. Jahn, Riverside, ll].

[73] Assignee: Chicago Metallic Corporation, Chicago, 111.

[22] Filed: Jan. 29, 1973 21 Appl. No: 327,700

Related U.S. Application Data [62] Division of Scr, No. 139,377, May 3,1971, Pat. No.

[52] U.S. Cl. 52/732, 52/484 [51] int. (31 E04b 5/55 [58] Field oilSearch 52/484, 489, 493, 720, 52/732, 730

[56] References Cited UNITED STATES PATENTS 2,066,205 12/1936 Keating52/732 X 2,389,171 11/1945 Urbain.....

2,47 8,060 8/1949 Spiess 52/493 3,352,071 11/1967 Suttcr 1 1 l t 52/4843,426,496 2/1969 Jones 52/732 X 3,708,941 1/1973 Cuckson 52/484 PrimaryExaminerPrice C. Faw, Jr. Attorney, Agent, or Firm-Hill, Gross, Simpson,Van Santen, Steadman, Chiara & Simpson [57] ABSTRACT 12 Claims, 9Drawing Figures PATENTEU 1 MEI 10$ 2 CONCEALED GRID SYSTEM This is adivision of application Ser. No. 139,377, filed May 3, 1971, now US.Pat. No. 3,714,753.

BACKGROUND OF THE INVENTION The invention is directed to a suspendedceiling grid structure for use in a concealed type of grid system inwhich the ceiling panels conceal the gird structure, i.e., the visibleedges of the respective panels abut one another. Systems of this typeusually employ panels which are provided with grooves or kerfs in theirperipheral edges, in which are received flange portions of the gridstructure upon which portions the panels are supported.

While it might be possible to interlock all the panels with the gridstructure, for example, by a simultaneous installation of grid structureand panels, it is usually desirable to provide access above thesuspended ceiling structure, i.e., to provide for the removability of atleast selected panels without requiring at least a partial dismantlingof the grid structure. Obviously, the provision of accessibility above asuspended ceiling involves greater problems in the case of a concealedgrid system as compared with an exposed grid system, in which the panelsare merely resting upon flanges of thr grid system and thus may bereadily raised out of engagement with the supporting grid structure andlaterally moved out of the way to provide the desired access.

Development of concealed grid systems providing acmodate the respectivegrid and panel components thereof.

More particularly, the present invention, in one of its preferred forms,utilizes a pair of support members or runners which are adapted toextend in spaced parallel relation between two spaced parallel mainrunners, with the ends of the support runners suitably carried by therespective main runners. The two pairs of runners thus define an accessspace which is adapted to be closed by one, or preferably, by a pair ofceiling panels, the juncture between the two panels being disposedcentrally between the two main runners whereby one edge of each panelmay be engaged with the adjacent portion of a main runner. Cooperablewith each support member is a supportable member for each panelemployed, a pair of portable members being employed with a pair ofceiling panels, with each member being adapted to be associated with oneof the ceiling panels cessibility thereabove have generally fallen intoone of two types, the first utilizing a substantially standard gridstructure of the concealed type with the peripheral edges of the panelsbeing so designed that at least some of the panels may be moved orpivoted upwardly and disengaged from the ceiling structure to permitaccess thereabove, while in the other type the runner structures are somodified that the portions of the runners supporting a selected panelare movable upwardly with the panel whereby the latter may be movedlaterally above the remaining panels to provide the desired access. Itwill be noted that in either of these general solutions to the problemit is necessary that the ceiling panels be pivoted or moved upwardlyabove the general plane of the ceiling and shifted laterally to providethe desired access. It will be apparent that this necessitates theprovision of adequate space above the panels to enable the same to bepivoted or moved to the desired positions necessary to provide adequateaccess. Oftentimes the requisite space therefor is not available eitherthroughout the ceiling structure, or at'certain locations, at whichaccessibility thus would be foreclosed.

The present invention is therefore directed to a novel runner structureand assembly as well as a novel grid structure utilizing the same, inwhich these disadvantages are completely eliminated.

BRIEF SUMMARY OF THE INVENTION The desired results are achieved in thepresent invention by the utilization of a novelstructure in whichaccessibility is achieved by moving the selected ceiling panel andportions of the supporting structure therefor downwardly, whereby thepanel involved may be readily removed from the supporting structure,providing free access to the space thereabove. As a result no additionalspace above the ceiling grid structure is required to provide'thedesired accessibility, only sufficient space being required above theceiling to accomalong the edges thereof adjacent the support members,one end of each supportable member being carried by the adjacent mainrunner, with the associated support member and adjacent supportablemember having cooperable means thereon for. interlocking the respectiveopposite ends of the supportable members to the adjacent portion of theassociated support member.

The construction 'of the interlocking means is such that theinterlocking action may be achieved by upward movement of the associatedportion of the supportable members relative to the cooperable supportmember and when so interlocked will support the associated ceiling panelin the plane of the ceiling. However, when it is desired to obtainaccess above such a ceiling panel, the interlocking portions of thesupport and supportablemembers for such panel may be disengaged topermit the adjacent portion of the ceiling panel to be moved downwardlyalong with the corresponding portions of the supportable members,following which the ceiling panel may be removed to provide the desiredaccess. Such disengagement may be readily effected by means of asuitable thin bladed tool which may be inserted between the support andsupportable members and suitably actuated to engage the top edge of sucha supportable member following which downwardly directed force may beapplied thereto through the tool.

ln'another preferred form, utilizing only a single pair of cooperablesupport and supportable members, the support member is provided withtile supporting flanges at each side thereof, one side having a portionwhich'is flangeless and adapted to receive and support the cooperablesupportable member thereat.

In both of the preferred embodiments of the invention the supportablemembers are provided with outwardly extending flanges thereon and theassociated ceiling panel is provided with a kerf on the correspondingedges as well as the end edge adjacent the main runner. Consequentlywhen the supportable member or members are moved downwardlytheassociated edge of the ceiling panel will move downwardly and as soonas such edge of the ceiling panel. has cleared the remainder of theceiling structure, it may be laterally slipped out of engagement withthemainrunner and removed. Replacement would follow in reverse order.

In the embodiment of the invention illustrated, the interlocking meansbetween a supportable member and the associated support member comprisesmeans on the support member forming a receiving space for a projectionsuch as a longitudinally extending bead on the upper edge of thesupportable member whereby, upon upward movement of the supportablemember relative to the support member such bead may be disposed in suchreceiving space, the element defining such space and/or such bead havingsufficient resiliency to permit sufficient springing thereof to effectan interlocking of the parts.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings wherein like referencecharacters indicate like or corresponding parts,

FIG. 1 is a perspective view looking down on a portion of a ceilingstructure illustrating one embodiment of the present invention;

FIG. 2 is a side elevational view of one of the grid assembliesillustrated in FIG. 1, with the main runners illustrated in section;

FIG. 3 is a transverse sectional view through the assembly illustratedin FIG. 2;

FIG. 4 is a side elevational view of the end portion of interlockingstructure on the support member;

FIG. 5 is a sectional view similar to that of FIG. 3, of a supportmember of slightly modified construction;

FIG. 6 is a perspective view, similar to FIG. 1, looking down on aportion of a ceiling structure illustrating another embodiment of thepresent invention;

FIG. 7 is a sectional view similar to FIG. 3 illustrating details of theembodiment illustrated in FIG. 6;

FIG. 8 is a side elevational view of the support runner illustrated inFIGS. 6 and 7; and

FIG. 9 is a sectional view similar to FIG. 5 illustrating a modifiedconstruction of the support runner illustrated in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings and moreparticularly to FIG. 1, the reference numeral 1 indicates generally aportion of a suspended ceiling grid structure of the concealed type,employing a plurality of main runners 2, which may be of a type commonlyemployed in prior grid structures. The main runners may be suitablyspaced, in parallel relation across the'area to be enclosed and suitablysupported by means disposed thereabove through the usual connections,for example tie wires 3. Suitable transversely extending runners 4,generally designated in the trade as cross tees" extend in spacedparallel relation between adjacent main runners, with the cross teesdisposed in aligned relation from one pair of main runners to the next.

Usually the ends of the cross tees are interlocked with the adjacentmain runner, one form of connection employing tongues formed out of aportion of the cross tees and adapted to extend through a verticallyextending slot in the main runner. While details of the various runnersand cross tees may vary, the substantially all have in common theutilization of an elongated runner structure having a substantiallyinverted T-shaped transverse cross section to form a verticallydirected, longitudinally extending central portion or webprovided at itslower longitudinal edge with oppositely directed horizontally extendingflanges adapted to suitably engage and support respective ceilingpanels. To provide reinforcement, the upper edge of the verticallyextending portion usually terminates in a longitudinally extending beadsuitably rolled or otherwise formed thereon. Most cross tees commonlyemployed are of similar inverted T construction and where secured ateach end to the main runners by respective-tongues formed on each end ofthe cross tees, such tongues are normally formed out of thevertically'directed web portion and adapted to be inserted in avertically extending slot in the vertically directed portion of the mainrunner. Various constructions have also been marketed incorporatingmeans on the tongue and/or on the main runner for effecting a mechanicalinterlock operative to restrict undesired withdrawing or disengagingmovement of the cross tee with respect to the main runner.

As will be apparent from a reference to FIG. 1, the general constructionof such a grid structure usually employs modular techniques wherebylight fixtures, etc., indicated generally by the numeral 5, may besupported between respective pairs of main runners and cross tees, thecross tees associated therewith, if necessary or desirable beingsuitably shaped to accommodate such a light fixture.

Extending between the main runners may be a plurality of similar crosstees 6 which are specifically designed to be disposed between andprovide support to adjacent panels 7.

Also extending between the main runners 2 are a pair of runner or crosstee assemblies indicated generally by the numeral 8, one such assemblybeing illustrated in elevation in FIG. 2 with details thereof beingillustrated in FIGS. 1 and 4. Each grid assembly 8 comprises a supportmember or runner 9 and a pair of supportable members or runners 10a and10b, which are of like general construction but with a reversal ofmounting and supporting elements.

The support runner 9, in the embodiment of the invention illustrated,may be formed from a single piece of strip stock suitably bent by arolling or other operation to form a vertically directed longitudinallyextending portion or web 11 terminating at its upper edge in alongitudinally extending hollow bead 12 and having along its lower edgea horizontally directed longitudinally extending flange 13, illustratedas being of double thickness, formed by bending the stock at the outerend of the flange and folding the same back upon itself as clearlyillustrated in FIG. 3. The opposite ends of the support member 9 may besuitably interlocked with the main runners 2, as, for example, by meansof longitudinally extending tongues 14 formed from the stock of theportion 11, which tongues extend through respective vertically extendingslots 15 in the respective main runners. If desired, the tongues 14 maybe provided with suitable means, as, for example, a struck-out detent14', adapted to engage the adjacent face of the runner 2 to interlockthe tongue 14 to the main runner.

The respective supportable members and 10b are each of generallyL-shaped configuration in transverse cross section, each having avertically directed longitudinally extending portion 16 terminating atits lower edge in a horizontally directed longitudinally extendingflange 17. The members 10a and 10b may be readily fabricated from thesame type of sheet metal stock utilized in the fabrication of thesupport member 9, and as illustrated in FIG. 4, which illustrates theconstruction of the left end of the member 10a as viewedin FIG. 2, theflange 17 is provided along its lower face with a longitudinallyextending downwardly directed bead 18 which terminates at a point spacedfrom the extreme end of the member by a distance somewhat greater thanthe transverse width of one of the flanges of the associated main runner2 whereby the extreme end of the flange 17 may rest directly and firmlyupon the upper surface of the cooperable flange on the main runner. Thebead 18 thus provides an effective maximum thickness of the flange 17which corresponds to the double thickness of the flange 13 of thesupport runner 9, and a reinforcement for the flange. The top edge ofthe vertically directed portion 16 of the supportable members a and 10bare respectively provided with like longitudinally extending beads 19which are disposed at the same side of the portion 16 as the flange 17,and as clearly shown in FIG. 3 in the embodiment illustrated the beads19 have an angular transverse cross section formed by the respectiveangular disposed faces 20 and 21 which may extend, for example, at anangle of 90 with respect to one another. It will be appreciated from areference to FIG. 2 that the only difference in the runners 10a and 10bin the embodiment illustrated is the fact that the bead 18 on the runner10a terminates adjacent the left-hand of the runner while that on therunner 10b terminates at the right end thereof whereby such end portionsmay be engaged, as previously described with the associated main runner2. If desired, both ends of the respective beads 18 may terminate atspaced points from the adjacent ends of the member, eliminating twodifferent constructions.

The supportable runners 10a and 10b are each adapted to be supported atone end by the adjacent cooperable main runner 2 and suitable means istherefore provided adjacent the opposite ends of each of the members 10aand 10b for suitably supporting the same from the support runner 9. Inthe embodiment of the invention illustrated, the means on the supportrunner 9 is adapted to operatively engage the bead 19 on the associatedsupportable member, such means, in each case, comprising a rectangularlyshaped member 22 which, as illustrated in FIG. 3, is adapted to befabricated from a part of the vertically directed portion 11 of thesupport runner, such portion being out along a pair of spaced parallelvertical lines 23 which are connected at their lower edges by ahorizontally extending cut 24 connecting the two vertical cuts. The flapthus formed may be bent upwardly at the junction of its upper edge withthe portion 11 and provided with a series of longitudinally extendingbends therein to provide a receiving space 25, disposed in the oppositeside of the portion 11 to that carrying the flange 13, with the innersurface of the space 25 being complemental to the respective portions ofthe bead 19 of the respective supportable members 10a and 10b.

As illustrated in FIG. 3, the lower free edge of the portion of thestrip 22 is provided with an outwardly and downwardly directed edgeportion 26, which forms a guiding lip for the bead 19 when therespective members 9 and 10 are to be assembled. The construction issuch that upon positioning of the bead 19 of a supportable member 10adjacent the lip 26 and the application of upwardly directed force onthe member 10, relative to the member 9, the member 22 may be sprungoutwardly sufficiently to permit reception of the bead 19 in thereceiving space 25, and at the same time some compression of the bead 19may take place to facilitate the reception thereof into such a receivingspace.

The stock employed in the fabrication of the respec: tive support andsupportable members preferably is such that while having adequatestrength to efficiently support cooperable ceiling panels, and providean effective interlock between the engaged members, the stock preferablyshould be as thin as practical for its supporting purposes, to enablethe interlocking of the respective members without requiring undueforce. However, it will be appreciated that as the runner 2 willinitially support the adjacent end of the cooperable supportable member10, with the: interlocking action taking place by a pivotal movement ofthe supportable member about its connection with the main runner,maximum springing of the member 22 will take place progressively in alongitudinal direction therealong due to the initially angularrelationship between the supportable runner and the support runner,enabling a relatively easy engagement between the respective parts.

panel 7' being adapted to be supported by one main runner and theadjacent pair of supportable runners 10. As illustrated in FIG. 3 eachpanel 7' may be provided with the usual type of kerf 27 in one end edgeand the two longitudinal edges, with the adjoining panel edges at thejuncture therebetween being suitably formed to mate, as, for example,having a plain vertical edge 28, illustrated in FIG. 3.

In assembling the panels 7 with the supporting structure thereof, acorresponding supportable member 10 is disposed adjacent thelongitudinal peripheral edges of the associated panel 7 with the flange17 of such member disposed in the corresponding kerf 27. The kerfed endof the panel and ends of the assembled supportable members 10 are thenengaged with the cooperable main runner by initially positioning thepanel in an angular relation, similar to that illustrated in FIG. 2,which, however, represents an exaggerated position, the panel preferablybeing retained as nearly horizontal as reasonably possible, followingwhich the opposite free end edge of the panel and associated members 10are moved upwardly, pivoting the assembly about its support with theassociated main runner 2, moving the assembly upward until it assumesthe position illustrated in FIG. 2 in which the parts assume thepositions illustrated in FIG. 3. The operation is then repeated with theother panel 7', completing the assembly. It will be appreciated thatwhile I have illustrated the meeting edge 28 of each of the panels asbeing a plain vertical edge, another edge configuration could beemployed as, for example, a lap joint such as is commonly employed insome'forms of panelling, in which caseassembly would have to be effectedin. a definite sequence, initially installing the panel having the upperoverlap at each juncture followed by the installation of the panelhaving the lower overlap thereat.. However, it is believed that in mostinstances a butt-type joint will be adquate, enabling the use ofidentical panels. It will be appreciated that to impart a uniformappearance to the ceiling structure it may be desired to construct thepanels 7 in two sections whereby such sections will have a juncture linethat matches that of the panel 7 and likcwise the panels 7, in suchcase, could employ either a butt, lap or other suitable edgeconfiguration, or its panels 7 could be provided with a score line orthe like simulating a juncture.

Access above the panels 7 may be readily achieved by reversing theinstallation procedures, employing a suitable tool in connectiontherewith. FIG. 2 illustrates the use of a novel tool, indicatedgenerally by the numeral having a handle 31 at one end and a flat planarblade 32 at the opposite end, which may be formed from stock similar tothat used in the blades of putty knives and the like, the blade 32,however, having a laterally extending projection 33 which provides anedge 34 adapted to engage the top edge of a supportable member 10adjacent the end thereof supported by the member 9. Thus, the blade 32is sufficiently thin that it may be readily inserted upwardly betweenthe parallel vertically directed portions 11 and 16 of the members 9 and10 respectively, until the entire portion 33 of the blade is disposedabove the top edge of the associated member 10. By then giving the toola slight axial twist in a direction to bring the edge 34 in an overlyingrelation with respect to the top edge of the member 10, the resultinginterlocking action between the tool and the end of the member 10 may beutilized to transmit downward force on the tool to the adjacent of themember, such force being increased until interlocking engagement betweenthe two members is broken. As soon as the one side has been disengagedthe supportable member at the opposite edge of the associated panel islikewise disengaged whereby such panel and the assembled supportablemembers may be removed. It will be appreciated that in each case it ismerely necessary that the panel edge at the juncture of the panels andassociated supportable members be pivoted downwardly sufficient topermit clearance of such end with the remaining panel, and that suchdownward movement is sufficient to effect the desired disengagement ofthe associated supportable members 10 from their cooperable supportmembers 9, and enable the panel to be disengaged from the associatedmain runner 2.

While FIGS. 2 and 3 illustrate a construction in which the interlocingmembers 22 are integrally formed from respective areas of the verticallydirected portion 11 of the support member, which it is believed is thesimplest and cheapest, as well as the most efficient construction, insome cases it may be desirable to form such interlocking means as aseparate element, particularly if, for example, it is desired to employstock therefor of greater resiliency than that of the members. Such aconstruction is illustrated in FIG. 5 wherein the support member 9 isprovided with a vertically directed portion 11 extending unbrokenthrough out its length, insofar as the interlocking means is concerned,and the member 22 is formed as a separate strip, the transverse crosssectional configuration of the I member 22 being identical to that ofthe member 22 with the exception that the member 22' is provided with anupwardly directed extension 35 which forms a mounting strip adapted tobe secured to the portion 11, for example, by a series of spot welding36 or other suitable means of securement It will be apparent that thegeneral operation of the construction of FIG. 5 is identical with thatof FIG. 3.

While I haveillustrated the bead 19 and the receiving space 25 as havingan angular cross sectional configu- 4 8 ration, such configuration maybe varied depending upon the application and details of construction,et.

Likewise, the number of accessible panels utilized in a ceilinginstallation may vary as desired, merely selected areas being providedwith accessible panels, or such accessible panels may be alternated byemploying a grid assembly consisting of a support member 9 and a pair ofsupportable members 10 for each panelsupporting cross tee in which casealternate panels would be permanently mounted on the flanges 13 ofoppositely disposed support runners 9 while the other intermediatepanels will be supported by respective pairs of supportable members 10.

It will also be noted that while I have illustrated the useof a pair ofsupportable members 10a and 10b with a single support member 9, in someapplications it may be desirable to utilize only a single panel to closea space between two support members in which case the supportablemembers 10 would each be of approximately the same length as a supportmember 9 with the interlocking member 22 being disposed adjacent onemain runner 2 and adapted to support the adjacent end of the supportablemember thereat. In this case the ceiling panels preferably would be sodesigned that the main runner 2 not providing the direct support of theceiling panel would be suitably concealed by a flange or underlap formedeither on the accessible panel or on an adjacent panel.

FIGS. 6 through 9 illustrate another preferred form of the invention inwhich only a single support member and a single supportable member isemployed, the remainder of the ceiling structure being of generallystandard construction and employing known types of runner members. Thisconstruction is particularly suitable where a concealed'structureemploying relatively small ceiling panels or tiles, for example 12 or 16inches square, disposed in a ceiling structure employing four foot basemodules. In such a construction the main runners would be disposed onfour foot centers with cross runners or cross tees extendingtherebetween and interlocked therewith at four foot intervals. Where 12square panel tiles are to be employed, three additional cross tees maybe disposed parallel to the interlocked cross tees in a non-interlockedrelation with respect to the main runners. Thus, employing 12 squaretiles, four rows of tiles would be utilized, each having a kerf in itsrespective peripheral edges adapted to receive the adjacent flange on amain runner, or on the respective interlocked and noninterlocked crossrunners or tees, and with the remaining inner edges of the tiles of arow disposed in abutting relation.

Referring to FIG. 6, the pair of main runners 2 are adapted to beconnected at four foot intervals by respective cross runners 8',generally constructed similar to the usual cross runner or tee, forexample the cross runners 4 illustrated in FIG. 1. Referring to FIGS. 7and 8, the'usual cross runner or cross tee is replaced by a runner orcross tee assembly, indicated generally by the numeral 8' comprising asupport member or runner 9 and a cooperable supportable member or runner10'.

The support runner 9, in the embodiment of the invention illustrated,may be constructed generally in the same manner as the usual cross tee,and in like manner having a vertically directed longitudinally extendingportion or web 11 terminating at its upper edge in a longitudinallyextending hollow bead 1'2 and having along its lower edge oppositelydirected longitudinally extending flanges 13 and 13', illustrated asbeing of double thickness, formed by bending the stock at the outer endof the flange 13 and again folding the material back upon itself to formthe oppositely disposed flange 13 at the other side of the web 11. Asillustrated in FIG. 8 the ends of the member 9 may be provided withtongues 14 and detents 14 as previously described in connection with themember 9. The construction thus far described is comparable to a knownform of cross tee. However, as will be apparent from a reference to FIG.6, the flange 13" is not continuous from one end of the member 9 to theopposite end thereof, the member having a section 35 which has atransverse cross section similar to that of the support member 9, i.e.,provided with only the flange I3.

Cooperable with the support member 9 is a supportable member lf) havinga cross section corresponding to that of the support members 10a or 10band of a length to readily be insertable in the section 35 to provide anextension thereat of the flange 13'. In like manner the web 11 of thesupport member 9" is provided with means engageable with the supportablemember 10 for supporting the same in operable relation from the supportrunner 9' and, in the embodiment of the invention illustrated, suchmeans is constructed in the same manner as the comparable meansillustrated in FIGS. 2 and 3, a pair of rectangular shaped members 22being formed from the stock of the web portion 11 to form flaps whichare adapted to receive the longitudinally extending bead 19 on thesupportable member 10'. Likewise, as illustrated in-FIG. 9, the flapsmay be constructed as individual elements 22, corresponding to theconstruction illustrated in FIG. 5. It will be appreciated that in theirembodiments the supportable member 10' may be moved upwardly andinterlocked with the support member 9' to form a cross tee assemblygenerally corresponding to the usual cross tee.

ln assembling a supporting grid structure employing the constructionillustrated in FIG. 6, the main runners can be installed in the usualmanner and connected at spaced intervals, for example, four feet, byrespective support members 9', Le, in the usual manner, merelysubstituting the support members 9 for the usual cross runners or crosstees. By similarly orienting each support member 9' each four foot spaceis defined by a pair of main runners and a pair of transverselyextending support members one of which may be provided with a cooperableremovable supportable member 10'.

The panel tiles 7 may then be arranged in rows, beginning adjacent theflange 13 of a support member and proceeding towards the flanges 13' ofthe opposite support member, disposing cross tees 6 between adjacentrows of panel tile. Upon the completion of three such rows of tiles theremaining row may be assembled by engaging a tile with the exposedflange of the adjacent cross tee, as indicated in dotted lines in FIG.7, rotating the tile upwardly until it is in proper alignment with theadjacent flange 13 and then laterally sliding the tile to its position.After three such tiles have been assembled, the last tile may bepositioned as illustrated in dotted lines in FIG. 7, the supportablemember 10 engaged therewith and the panel rotated upwardly to theposition illustrated in solid lines in FIG. 7, snapping the supportablemember 10 into locking engagement with the support member 9. In sorotating the final tile upwardly, the supportable member 10' may besprung slightly, if necessary, to clear the adjacent tile.

.lf access above the ceiling is desired, a suitable tool, such as thetool 30, illustrated in FIG. 2 may be employed to effect a disconnectionof the supportable member 10' from the support member9, therebyreversing the installation process.

It will be appreciated that in this construction the section 35,carrying only the flange l3, and of a width somewhat greater than thatof a single tile, may be correspondingly disposed anywhere along thesupport member 9, and could therefore, if desired, be disposed adjacentone end of the support member. However, for most applications, it isdeemed preferable to dispose such section intermediate the ends of therunner whereby the end portions of the support member at the crossmembers 2 are identical in construction to assure a firm interlockedconnection.

While I have illustrated in FIG. 6, a construction using tiles forexample, which are one foot square, if it were desired to employ threerows of 16 inch tile, the section 35 would be increased to accommodatethe larger tile or panel.

It will be appreciated that where the supportable member 10 is disposedintermediate the ends of the support member and thus between dlangeportions 13' the bead 18 along the flange 17 of the supportable membermay be continuous from end to end.

As previously mentioned, if the support members 9' are similarlyoriented access above the ceiling may be provided for each four footmodule. However, if desired, the assemblies 8 may be substituted forselected cross-runners to provide access merely at selected portions ofthe ceiling structure.

It will be particularly noted that in either of the embodimentsillustrated the general assembly of the supporting grid structure iscomparable to existing techniques, with the changes in assembly of theceiling panels being readily apparent and thus substantiallyselfexplanatory. Reeducation of installing personnel is thereforereduced to a minimum.

Having thus described my invention it will be obvious that various andmaterial modifications may be made in the same without departing fromthe spirit of my invention.

What I claim'i s:

l. A runner structure for use in a grid assembly forming a part of aconcealed type of grid system with accessibility above the panels to besupported thereby, comprising a support member, and a supportable memberadapted to be supported from said support member, said support memberbeing constructed at its ends for engagement with respective mainrunners for support thereby, said support and supportable members eachhaving a vertically directed longitudinally extending portionterminating at its lower edge in a longitudinal flange extendinghorizontally outward from a face of the associated vertically directedportion, said support member having means thereon extending laterallyoutwardly from the opposite face of said vertically directed portionforming means for interlocking engagement with cooperable means on saidsupportable member, said means on said support member being constructedfor engagement with such cooperable means by upward movement of thelatter means relative to said support member, with said verticallydirected longitudinally extending portions in side-by-side relation andsaid flanges extending laterally outwardly in opposite directionstherefrom and disposed in a common plane, such cooperable means beingdisengageable upon application of downwardly directed force upon suchadjacent portion of such an engaged supportable member.

2. A runner member according to claim 1, wherein said support member isof generally L-shape in transverse cross-section.

3. A runner member for use in a grid assembly forming a part of aconcealed type of grid system with accessibility above the panels to besupported thereby, comprising a support member constructed at its endfor engagement with respective main runners for support thereby, saidsupport member having a vertically directed longitudinally extendingportion terminating at its lower edge in a longitudinal flange extendinghorizontally outward from a face of said vertically directed portion,said support member having means thereon extending laterally outwardlyfrom the opposite face of said vertically directed portion forming meansfor interlocking engagement with cooperable means on a supportablemember adapted to be supported from said support member, said means onsaid support member being constructed for engagement with suchcooperable means by upward movement of the latter means relative to saidsupport member, whereby such cooperable means may be disengaged upon theapplication of downwardly directed force upon such adjacent portion ofsuch an engaged supportable member, said support member also having alongitudinal flange means extending horizontally outward from the otherface of said vertically directed portion, the section of said memberadjacent said first mentioned means being generally L-shape intransverse cross-section.

4. A runner member according to claim 3, wherein said flange meanscomprises a pair of spaced aligned flanges, the adjacent ends of whichdefine the length of ,said L-shaped section.

5. A runner member according to claim 1, wherein said means on saidsupport member forms a receiving space for means interlocable therewithon such a supportable member.

6. A grid runner member according to claim 5, wherein said means formingsaid receiving space includes at least a relatively resilient portion,whereby the interlockable means on such other member may enter saidreceiving space by temporarily springing said resilient portion out ofits normal position.

7. A runner member for use in a grid assembly forming a part of aconcealed type of grid system with accessibility above the panels to besupported thereby, comprising a support member constructed at its endsfor engagement with respective main runners for support thereby, saidsupport member having a vertically directed longitudinally extendingportion terminating at its lower edge in a longitudinal flange extendinghorizontally outward from a face of said vertically directed portion,said support member having means thereon extending laterally outwardlyfrom the opposite face of said vertically directed portion forming meansfor interlocking engagement with cooperable means on a supportablemember adapted to be supported from said support member, said means onsaid support member being constructed for engagement with suchcooperable means by upward movement of the latter means relative to saidsupport member, whereby such cooperable means may be disengaged upon theapplication of downwardly directed force upon such adjacent portion ofsuch an engaged supportable member, said means on said support memberforming a receiving space for means interlockable therewith on such asupportable member, and includes at least a relatively resilientportion, whereby the interlockable means on such other member may entersaid receiving space by temporarily springing said resilient portion outof its normal position, said means forming a receiving space comprisinga generally rectangularly-shaped relatively resilient strip of materialcut from the material of the vertically directed portion of said supportmember, said strip being joined along its upper edge to said portion andextending outwardly and downwardly therefrom, the lower portion of suchstrip being formed to provide said receiving space at the inner sidethereof.

8. A runner member for use in a grid assembly forming a part of aconcealed type of grid system with accessibility above the panels to besupported thereby, comprising a support member constructed at its endsfor engagement with respective'main runners for support thereby, saidsupport member having a vertically directed longitudinally extendingportion terminating at its lower edge in a longitudinal flange extendinghorizontally outward from a face of said vertically directed portion,said support member having means thereon extending laterally outwardlyfrom the opposite face of said vertically directed portion forming meansfor interlocking engagement with cooperable means on a supportablemember adapted to be supported from said support member, said means onsaid support member being constructed for engagement with suchcooperable means by upward movement of the latter means relative to saidsupport member, whereby such cooperable means may be disengaged upon theapplication of downwardly directed force upon such adjacent portion ofsuch an engaged supportablemember, said means on said support memberforming a receiving space for means interlockable therewith on such asupportable member, and includes at least a relatively resilientportion, whereby the interlockable means on such other member may entersaid receiving space by temporarily springing said resilient portion outof its normal position, said means forming a receiving space comprises agenerally rectangularly-shaped relatively resilient strip of material,said striphaving its upper edge portion seated upon and joined to saidvertically directed portion and extending outwardly and downwardlytherefrom, the lower portion of such strip being formed to provide saidreceiving space at the inner side thereof.

9. A runner member according to claim 1, wherein said cooperable meanscomprises a projection constructed to enter a receiving space on such asupport member for effecting an interlock between the two members.

10. A runner member according to claim 9, wherein said projection is inthe form of a laterally offset bead extending longitudinally along thetop edge portion of the vertically directed portion of said othermember.

11. A grid structure according to claim 10, wherein said bead is ofangular transverse cross-section.

12. A runner member according to claim 1, wherein said supportablemember is constructed at one end for engagement with and support by theflange of a transversely extending runner.

1. A runner structure for use in a grid assembly forming a part of aconcealed type of grid system with accessibility above the panels to besupported thereby, comprising a support member, and a supportable memberadapted to be supported from said support member, said support memberbeing constructed at its ends for engagement with respective mainrunners for support thereby, said support and supportable members eachhaving a vertically directed longitudinally extending portionterminating at its lower edge in a longitudinal flange extendinghorizontally outward from a face of the associated vertically directedportion, said support member having means thereon extending laterallyoutwardly from the opposite face of said vertically directed portionforming means for interlocking engagement with cooperable means on saidsupportable member, said means on said support member being constructedfor engagement with such cooperable means by upward movement of thelatter means relative to said support member, with said verticallydirected longitudinally extending portions iN side-by-side relation andsaid flanges extending laterally outwardly in opposite directionstherefrom and disposed in a common plane, such cooperable means beingdisengageable upon application of downwardly directed force upon suchadjacent portion of such an engaged supportable member.
 2. A runnermember according to claim 1, wherein said support member is of generallyL-shape in transverse cross-section.
 3. A runner member for use in agrid assembly forming a part of a concealed type of grid system withaccessibility above the panels to be supported thereby, comprising asupport member constructed at its end for engagement with respectivemain runners for support thereby, said support member having avertically directed longitudinally extending portion terminating at itslower edge in a longitudinal flange extending horizontally outward froma face of said vertically directed portion, said support member havingmeans thereon extending laterally outwardly from the opposite face ofsaid vertically directed portion forming means for interlockingengagement with cooperable means on a supportable member adapted to besupported from said support member, said means on said support memberbeing constructed for engagement with such cooperable means by upwardmovement of the latter means relative to said support member, wherebysuch cooperable means may be disengaged upon the application ofdownwardly directed force upon such adjacent portion of such an engagedsupportable member, said support member also having a longitudinalflange means extending horizontally outward from the other face of saidvertically directed portion, the section of said member adjacent saidfirst mentioned means being generally L-shape in transversecross-section.
 4. A runner member according to claim 3, wherein saidflange means comprises a pair of spaced aligned flanges, the adjacentends of which define the length of said L-shaped section.
 5. A runnermember according to claim 1, wherein said means on said support memberforms a receiving space for means interlocable therewith on such asupportable member.
 6. A grid runner member according to claim 5,wherein said means forming said receiving space includes at least arelatively resilient portion, whereby the interlockable means on suchother member may enter said receiving space by temporarily springingsaid resilient portion out of its normal position.
 7. A runner memberfor use in a grid assembly forming a part of a concealed type of gridsystem with accessibility above the panels to be supported thereby,comprising a support member constructed at its ends for engagement withrespective main runners for support thereby, said support member havinga vertically directed longitudinally extending portion terminating atits lower edge in a longitudinal flange extending horizontally outwardfrom a face of said vertically directed portion, said support memberhaving means thereon extending laterally outwardly from the oppositeface of said vertically directed portion forming means for interlockingengagement with cooperable means on a supportable member adapted to besupported from said support member, said means on said support memberbeing constructed for engagement with such cooperable means by upwardmovement of the latter means relative to said support member, wherebysuch cooperable means may be disengaged upon the application ofdownwardly directed force upon such adjacent portion of such an engagedsupportable member, said means on said support member forming areceiving space for means interlockable therewith on such a supportablemember, and includes at least a relatively resilient portion, wherebythe interlockable means on such other member may enter said receivingspace by temporarily springing said resilient portion out of its normalposition, said means forming a receiving space comprising a generallyrectangularly-shaped relatively resilient strip of material cut from thematerial of the vertically dirEcted portion of said support member, saidstrip being joined along its upper edge to said portion and extendingoutwardly and downwardly therefrom, the lower portion of such stripbeing formed to provide said receiving space at the inner side thereof.8. A runner member for use in a grid assembly forming a part of aconcealed type of grid system with accessibility above the panels to besupported thereby, comprising a support member constructed at its endsfor engagement with respective main runners for support thereby, saidsupport member having a vertically directed longitudinally extendingportion terminating at its lower edge in a longitudinal flange extendinghorizontally outward from a face of said vertically directed portion,said support member having means thereon extending laterally outwardlyfrom the opposite face of said vertically directed portion forming meansfor interlocking engagement with cooperable means on a supportablemember adapted to be supported from said support member, said means onsaid support member being constructed for engagement with suchcooperable means by upward movement of the latter means relative to saidsupport member, whereby such cooperable means may be disengaged upon theapplication of downwardly directed force upon such adjacent portion ofsuch an engaged supportable member, said means on said support memberforming a receiving space for means interlockable therewith on such asupportable member, and includes at least a relatively resilientportion, whereby the interlockable means on such other member may entersaid receiving space by temporarily springing said resilient portion outof its normal position, said means forming a receiving space comprises agenerally rectangularly-shaped relatively resilient strip of material,said strip having its upper edge portion seated upon and joined to saidvertically directed portion and extending outwardly and downwardlytherefrom, the lower portion of such strip being formed to provide saidreceiving space at the inner side thereof.
 9. A runner member accordingto claim 1, wherein said cooperable means comprises a projectionconstructed to enter a receiving space on such a support member foreffecting an interlock between the two members.
 10. A runner memberaccording to claim 9, wherein said projection is in the form of alaterally offset bead extending longitudinally along the top edgeportion of the vertically directed portion of said other member.
 11. Agrid structure according to claim 10, wherein said bead is of angulartransverse cross-section.
 12. A runner member according to claim 1,wherein said supportable member is constructed at one end for engagementwith and support by the flange of a transversely extending runner.